A law stating that the volumes of gases undergoing a reaction at constant pressure and temperature are in a simple ratio to each other and to that of the product.‘Charles' law also is known as Gay-Lussac's law and the constant pressure law.’
- ‘This important elaboration came to be known as Gay-Lussac's law of combining volumes.’
- ‘This law provides an explanation for why Gay-Lussac's law of combining volumes works.’
- ‘If this was the right formula for water, then both Gay-Lussac's law of combining volumes and Lavoisier's law of conservation of mass could not be right.’
- ‘Today, Gay-Lussac's law is stated as follows: The ratio of the volumes of gases consumed or produced in a chemical reaction is equal to the ratio of simple whole numbers.’
Early 19th century named after Joseph L. Gay-Lussac (1778–1850), French chemist and physicist.